The Hertfordshire Half Marathon & 10K in support of Garden House Hospice returns for 2026. Taking place on Sunday 1st November, this exciting event begins and ends at Knebworth House, with scenic closed-road countryside paths and the beautiful surroundings of Knebworth Park, offering runners of all abilities a memorable race experience.

Both races feature undulating, scenic road routes through the picturesque Hertfordshire countryside. Whether you’re tackling the Half Marathon or the 10K, you’ll enjoy a welcoming race-day atmosphere, excellent support from marshals, and clear route markings. It’s the perfect autumn challenge for seasoned runners aiming for a new PB or first-timers stepping up their distance.